The invention relates to switch and interrupter mechanisms, and more particularly to operating rods for moving the movable contact of such mechanisms.
A known switch or interrupter mechanism includes a first contact that is axially movable toward and away from a fixed contact. The mechanism is enclosed within a vessel containing a dielectric fluid, such as SF.sub.6 gas, which has a low dielectric constant. A prime mover provides the energy for moving the first contact and is connected thereto by an operating rod. Typically, the operating rod includes an insulating portion having a high dielectric constant and having thereon a conductive portion or end fitting that is pivotally connected to the first contact by a pin.
The point at which the conductive fitting, the high-dielectric-constant insulating portion and the low-dielectric-constant gas meet is known as a triple point. The triple point is subject to high electrical stress. In the past, stress relief has been provided by placing a grading shield over the triple point.